1. Physical Barrier
The galvanized coating acts as a dense metal shield over steel pipe. More stable than iron, zinc blocks moisture, oxygen, acid, alkali and salt spray. Steel stays protected as long as the zinc film remains intact.
2. Cathodic Protection: Zinc Sacrifices Itself
Zinc is more electro‑chemically active. In corrosive conditions, zinc corrodes first to safeguard iron. Even scratches will still be protected by surrounding zinc, which makes galvanized steel outperform regular paint coatings.
3. Self‑healing Effect
Mild corrosion produces dense basic zinc carbonate (“white rust”). Unlike expanding iron rust, this adheres tightly, seals off air and water, and delivers secondary protection to extend coating service life.